1. Field of the Invention
The present invention relates to fluid, generally hydraulic, testing of a single connection between tubular members, and more specifically to a method and apparatus for pressure testing a single connection from the inside of a single pipe end to the exterior of a pipe coupling connected at one of its ends with the single pipe end. A body includes longitudinally spaced annular seal-lock ring segment assemblies for respectively sealingly engaging and locking with the interior of the pipe and with the pipe coupling threadedly engaged therewith to form a chamber across the single connection for receiving test fluid when the seal and lock ring segment assemblies are expanded into engagement with the pipe and pipe coupling. Fluid passage means are provided for conducting pressure fluid to expand the seal and lock ring segment assemblies into sealing engagement with the pipe end and pipe coupling and a second fluid passage is provided for communicating test fluid pressure to the chamber. The integrity of the threaded connection between the single pipe end and the pipe coupling is determined by visually noting leakage exterior of the pipe at the end of the pipe coupling, or by instrumentally noting a leakage by a decrease in the test pressure in the chamber when it is maintained under fluid pressure.
2. Description of the Prior Art
So far as known to Applicant, there has never been provided any type of arrangement for testing a single connection between a pipe end threadedly engaged in only one end of a pipe coupling for determining the integrity of the threaded connection. Ordinarily after a pipe coupling is threadedly engaged on a pipe end at the pipe mill, the threaded connection is tested. Quite often the pipe collar becomes partially dislodged from the pipe end during transport from the mill to its ultimate location for use. Heretofore, as pipe is run into the well bore, a joint of pipe is threadedly engaged with the other end of the pipe coupling, and the threaded connections at each end of the pipe coupling, that is the threaded connection termed the "mill end" and the just completed threaded connection on the rig floor, are simultaneously tested before lowering into the well. Most leaks which are discovered while testing in this manner as the pipe is run into the well occur on the so called "mill end"--that is, on the threaded pipe end on which the pipe coupling was initially engaged at the mill. It can be appreciated that substantial time and expense is incurred not only in testing for leaks in tubular connections as they are run into a well bore, but further substantial expense is incurred in attempting to correct such improperly threaded connections.
The present invention provides a relatively simple device which can be readily inserted into the single pipe end that is threadedly engaged at one end of a pipe coupling for sealing off therebetween and effecting a pressure test of the threaded connection between the single pipe end and the pipe coupling before it is placed on the rig floor to be run into the well. This operation cannot be performed on the rig floor after a tubular member has been threadedly connected into the other end of the pipe coupling, since at that time only both ends of the pipe coupling may be readily subjected to internal pressure testing and even then only under the conditions as they exist at the well location site.
It can be appreciated that the equipment presently utilized to test at the well site on a rig floor as the pipe is run into the well is substantial in size and is difficult to manipulate and position for each joint. Testing of threaded connections as the pipe is run into the well is done under substantial stress as it is desired to lower the pipe into the well bore as rapidly as possible to avoid any complications from any number of sources that can occur. It is always desirable to run the pipe as rapidly as possible to avoid sticking, and it can therefore be appreciated that it is desirable to conduct the test operations as quickly as possible. It would be difficult, if not impossible, to lower and properly locate a tool into a well pipe in a well bore to internally test only one end on the rig floor as the pipe is run into the well.
The present invention enables the single pipe end which is threadedly engaged with a coupling to be pressure tested before it is engaged with another tubular member and run into the well, which may reduce, if not eliminate, the need for testing the threaded connections between tubular members as they are run into the well and all the problems presently encountered with such procedure.
The present invention provides an apparatus for inserting in a pair of members having a single connection therebetween, which apparatus is provided with means to seal and lock the apparatus in position to form a sealed test chamber across the single connection and retain the apparatus in position even under test pressures up to or exceeding 15,000 psi and even where the members are of different diameter subjecting the apparatus to differential loading.
Other objects and advantages of the present invention will become more readily apparent from a consideration of the following description and drawings.